Automatic power line disconnect apparatus

ABSTRACT

A power line disconnect apparatus includes a housing; an electrical connector that projects from a surface of a connector plate coupled to the housing, the electrical connector configured to receive a plug of a power cable; an ejector pin configured to project through a first aperture in the connector plate and eject the plug from the electrical connector; a microswitch configured to activate and deactivate a power circuit associated with the power cable; and a sensor pin configured to project through a second aperture in the connector plate, the sensor pin having a sensor pin extension, the sensor pin extension configured to control the microswitch.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/073,404 filed on Mar. 17, 2016, which is hereby incorporated byreference in its entirety.

TECHNICAL FIELD

This disclosure is directed generally to electrical connections and moreparticularly to a power line auto-disconnect apparatus for use with anelectrical power connection.

BACKGROUND

Emergency vehicles (such as fire trucks and ambulances), recreationalvehicles, and power boats, often utilize power lines that are connectedto stationary power sources for supplying electrical power for startingengines, charging batteries, and other purposes. However, such vehiclesmay need to uncouple swiftly from the power line when they are to bedriven away in response to an emergency, or the like. Consequently, themating power line plug should eject on activation of the vehicle'sengine, and also should eject in a manner that reduces or eliminatesdrawing an arc between the plug and the vehicle connector. Arcing, ifnot suppressed, is a major source of wear on contacts in both thevehicle connector and the plug. It is this wear that significantlyreduces the service life of these components.

SUMMARY

This disclosure provides a power line auto-disconnect apparatus for usein an electrical power connection.

In a first embodiment, a power line disconnect apparatus includes ahousing; an electrical connector that projects from a surface of aconnector plate coupled to the housing, the electrical connectorconfigured to receive a plug of a power cable; an ejector pin configuredto project through a first aperture in the connector plate and eject theplug from the electrical connector; a microswitch configured to activateand deactivate a power circuit associated with the power cable; and asensor pin configured to project through a second aperture in theconnector plate, the sensor pin having a sensor pin extension, thesensor pin extension configured to control the microswitch.

In a second embodiment, a vehicle includes an engine and a power linedisconnect apparatus attached to a surface of the vehicle. The powerline disconnect apparatus includes a housing; an electrical connectorthat projects from a surface of a connector plate coupled to thehousing, the electrical connector configured to receive a plug of apower cable; an ejector pin configured to project through a firstaperture in the connector plate and eject the plug from the electricalconnector; a microswitch configured to activate and deactivate a powercircuit associated with the power cable and the vehicle; and a sensorpin configured to project through a second aperture in the connectorplate, the sensor pin having a sensor pin extension, the sensor pinextension configured to control the microswitch.

Other technical features may be readily apparent to one skilled in theart from the following figures, descriptions, and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of this disclosure and its features,reference is now made to the following description, taken in conjunctionwith the accompanying drawings, in which:

FIG. 1 shows an external perspective view of an auto-disconnectapparatus for use in an electrical power connection, according to thisdisclosure;

FIG. 2 shows a perspective view of the auto-disconnect apparatus of FIG.1 from another angle;

FIG. 3 shows another perspective view of the auto-disconnect apparatusof FIG. 1;

FIG. 4 shows yet another perspective view of the auto-disconnectapparatus of FIG. 1 from a different angle;

FIG. 5 shows a side section view of the auto-disconnect apparatus ofFIG. 1 with a plug connected to the auto-disconnect apparatus; and

FIG. 6 illustrates an electrical schematic diagram of theauto-disconnect apparatus of FIG. 1.

DETAILED DESCRIPTION

The figures, discussed below, and the various embodiments used todescribe the principles of the present disclosure in this patentdocument are by way of illustration only and should not be construed inany way to limit the scope of this disclosure. Those skilled in the artwill understand that the principles of the present disclosure may beimplemented in any type of suitably arranged device or system.

As described above, some vehicles—particularly emergency vehicles—mayneed to quickly uncouple a connected power line when the vehicles are tobe driven away in response to an emergency, or the like. Consequently,the mating power line plug should eject on activation of the vehicle'sengine, but also it must eject in a manner that reduces or eliminatesdrawing an arc between the plug and the vehicle. Arcing, if notsuppressed, is a major source of wear on contacts in both the vehicleconnector and the plug. It is this wear that significantly reduces theservice life of these components.

To address these and other issues, embodiments of this disclosureprovide a power line auto-disconnect apparatus that includes a sealedhousing on which an electrical connector is mounted. Typically, thepower line auto-disconnect apparatus is mounted (or otherwise coupled)to a sidewall or other body portion of an emergency vehicle (e.g., afire truck or ambulance), a recreational vehicle, or a power boat.During use, the electrical connector mates with an electrical plug thatis part of a shore cable. Once connected, the shore cable iselectrically coupled to an engine starting circuit or battery on thevehicle. Voltage that is applied to the starter when the engine iscranked is also applied to a solenoid in the automatic power linedisconnect apparatus. The solenoid operates an ejector mechanism whichis mounted in the housing. The ejector mechanism ejects the shore cablefrom the apparatus, and a switch that is mounted in the housinginterrupts the current prior to the completion of the ejection action,thereby preventing arcing at the connector contacts and assuring longcontact life.

FIGS. 1 through 5 illustrate various views of an auto-disconnectapparatus 100 for use in an electrical power connection, according tothis disclosure. The embodiments of the auto-disconnect apparatus 100illustrated in FIGS. 1 through 5 are for illustration only. Otherembodiments could be used without departing from the scope of thisdisclosure.

FIG. 1 shows an external perspective view of the auto-disconnectapparatus 100. The auto-disconnect apparatus 100 includes a housingcomprising a front housing 102 and a rear housing 104. A part of thehousing (e.g., the front housing 102) includes multiple wire ports 106.Typically, there are two wire ports 106, although in some embodimentsthere may be more or fewer wire ports 106. As shown in FIG. 1, a plug108 is engaged with the front housing 102 of the auto-disconnectapparatus 100, concealing a male connector (which is shown in FIG. 4 asthe male connector 404). The plug 108 is at the end of a shore cable110. The plug 108 and the shore cable 110 are not part of theauto-disconnect apparatus 100.

The auto-disconnect apparatus 100 is typically coupled to a vehicle 112(e.g., mounted to a sidewall of the vehicle 112) and electricallycoupled to a battery charger or other device on the vehicle 112 thatrequires alternating current power. The auto-disconnect apparatus 100may include one or more mounting or attachment components (e.g.,brackets, fasteners, mounting holes, and the like) to secure theauto-disconnect apparatus 100 to the vehicle 112.

FIG. 2 shows a perspective view of the auto-disconnect apparatus 100from another angle with the rear housing 104 removed and the fronthousing 102 shown in transparent view. In FIG. 2, various internalcomponents of the auto-disconnect apparatus 100 are visible, including amicroswitch 202, an ejector arm 204, a support bracket 206, a pin 208,and tension springs 212.

The microswitch 202 activates and deactivates a power circuit thatincludes the shore cable 110, the auto-disconnect apparatus 100, and thevehicle 112, as described in greater detail below. When the microswitch202 activates the power circuit, power can be supplied from the cable110 through the auto-disconnect apparatus 100, to the vehicle 112. Whenthe microswitch 202 deactivates the power circuit, no current flows fromthe cable 110 to the vehicle 112. In some embodiments, the microswitch202 includes three contacts: normally open (NO), normally closed (NC),and common (C).

One end of the ejector arm 204 is pivotally mounted on the supportbracket 206 by means of the pin 208. The ejector arm 204 makes contactwith the ejector pin 210 at approximately a mid-point of the ejector arm204. The ejector pin 210 is configured to move longitudinally back andforth, as indicated by the dashed arrows. A pair of tension springs 212(only one of which is visible in FIG. 2) coupled to the second end ofthe ejector arm 204 provide continuous force on the ejector arm 204 andthe ejector pin 210 in the direction of the plug 108.

FIG. 3 shows a perspective view of the auto-disconnect apparatus 100with both the front housing 102 and the rear housing 104 removed. Inthis view, it can be seen that the microswitch 202 includes amicroswitch arm 302, one end of which is connected to and selectivelyactivates and deactivates the microswitch 202 in response to movement ofthe microswitch arm 302. The microswitch arm 302 extends away from themicroswitch 202 and, at the end of the microswitch arm 302, makescontact with a sensor pin extension 304. The sensor pin extension 304 isfixedly coupled to and extends laterally outward from a sensor pin 402,which is not visible in FIG. 3, but can be seen in FIGS. 4 and 5. Thesensor pin 402 is configured to move longitudinally within a sensor pinguide 306, in a direction of movement that is substantially parallel tothe movement of the ejector pin 210, as indicated by the dashed arrowsin FIG. 5. The sensor pin guide 306 is generally cylindrical and fixedlysecured inside the auto-disconnect apparatus 100. The sensor pin guide306 constrains and guides the movement of the sensor pin 402. The sensorpin guide 306 also includes a side opening 308 that extends through andlongitudinally along a wall of the sensor pin guide 306. The sensor pinextension 304 protrudes from the sensor pin 402 through the side opening308 and extends to make contact with the microswitch arm 302, as shownin FIG. 3.

FIG. 4 shows another perspective view from a different angle of theauto-disconnect apparatus 100 with both the front housing 102 and therear housing 104 removed. In this view, the plug 108 is not coupled tothe auto-disconnect apparatus 100. Without the plug 108, it can be seenthat the auto-disconnect apparatus 100 includes the sensor pin 402 and amale connector 404. The male connector 404 extends outside of the fronthousing 102 so as to be visible from the exterior. Of course, in someembodiments, the male connector 404 may be protected by a cover that ismoveable to reveal the male connector 404. A connector plate 406 iscoupled to the front housing 102 and surrounds the male connector 404.The sensor pin 402 and the ejector pin 210 pass through respectiveapertures of the connector plate 406. The sensor pin 402 is springloaded to be biased in an outward position, such as shown in FIG. 4. Themale connector 404 is configured to engage with a female connector atthe end of the plug 108. FIG. 5 shows a side section view of theauto-disconnect apparatus 100 with the plug 108 connected to theauto-disconnect apparatus 100. When connected, the male connector 404and the plug 108 form an electrical connection for electrical current toflow from the shore line 110 to the auto-disconnect apparatus 100 and tothe vehicle 112. Typically, the electrical current is provided at 110Vor 220V, although any suitable electrical source at any suitable voltagecould be used.

As shown in FIG. 4, the contacts of the male connector 404 aresignificantly longer than the projection of the sensor pin 402. However,the exposed portion of the ejector pin 210 is longer than the contactsof the male connector 404 when the ejector pin 210 is fully extendedoutward. In one aspect of operation, as the plug 108 is inserted forengagement with the auto-disconnect apparatus 100, the plug 108 firstmakes contact with the ejector pin 210 and then with the contacts of themale connector 404. As the plug 108 is inserted, the plug 108 pushes theejector pin 210 inward and the female connector of the plug 108 slidesover the contacts of the male connector 404. The movement of the ejectorpin 210 pushes the ejector arm 204 inward, against the force of thetension springs 212. As the plug 108 is further inserted, the plug 108contacts the sensor pin 402 and pushes the sensor pin 402 inward, whilealso continuing to depress the ejector pin 210. The sensor pin 402 moveswith the connected sensor pin extension 304, which in turn depresses themicroswitch arm 302 inward. When the plug 108 is fully engaged againstthe connector plate 406, a trigger locks the ejector arm 204 intoposition. With the microswitch arm 302 depressed inward, the microswitch202 and corresponding power circuit are activated to apply power fromthe plug 108 to the auto-disconnect apparatus 100 and to the vehicle112. Any electrical arcing that may result from the activation of theelectrical current when the plug 108 is engaged with the auto-disconnectapparatus 100 would occur inside the microswitch 202, which isconstructed to absorb arcing occurrences.

Typically, when the shore cable 110 is plugged into the auto-disconnectapparatus 100, the shore cable 110 will remain plugged in until thevehicle 112 is started. When the vehicle 112 is started (e.g., when thevehicle's engine is started), a solenoid (not shown) in theauto-disconnect apparatus 100 releases the trigger that frees theejector arm 204 from its locked position. The tension springs 212 causemovement of the ejector arm 204 towards the plug 108, which in turncauses the ejector arm 204 to advance the ejector pin 210 toward theplug 108. This is turn pushes the plug 108 out, and decouples the plug108 from the male connector 404 and the auto-disconnect apparatus 100.

In some similar auto-disconnect systems, if a shore cable is manuallyunplugged and the vehicle is not started, the current through the shorecable would continue to flow until the moment that the plug isdisconnected from the auto-disconnect system. This situation couldcreate an arc at the male connector and/or the plug, thereby shorteningthe life of the connectors.

To avoid such an occurrence, the auto-disconnect apparatus 100 uses theposition of the sensor pin 402 and the sensor pin extension 304 tocontrol the current into the auto-disconnect apparatus 100. When thesensor pin 402 is depressed by the plug 108, the sensor pin extension304 presses on the microswitch arm 302, thereby activating the powercircuit, which applies power from the plug 108 to the auto-disconnectapparatus 100 and to the vehicle 112. When the shore cable 110 isunplugged, as the plug 108 is decoupled from the connector plate 406,the spring-biased sensor pin 402 moves outward and the connected sensorpin extension 304 moves with the sensor pin 402. The movement of thesensor pin extension 304 causes the microswitch arm 302 to move outwardand causes the microswitch 202 and corresponding power circuit to bedeactivated. This stops the current flow through the male connector 404,the plug 108, and the shore cable 110. Because the full movement of thesensor pin 402 is less than the length of the contacts of the maleconnector 404, the outward movement of the microswitch arm 302, sensorpin extension 304, and sensor pin 402 are completed (and thus the powercircuit is interrupted) before the plug 108 is fully disengaged from themale connector 404. This ensures that no arcing can occur at the maleconnector 404 and/or the plug 108.

Because the sensor pin 402 and sensor pin extension 304 are not directlycoupled to the ejector pin 210 or the ejector arm 204, the movement ofthe pin 402 and extension 304 (and their control of the microswitch 202)is not dependent on the position of the ejector pin 210 or the ejectorarm 204. Stated another way, the control of the microswitch 202 and thepower circuit are independent of the position of the ejector pin 210.Thus, even if the plug 108 is manually removed and the ejector pin 210is not released, the power circuit will still be interrupted before theplug 108 is completely removed. Thus, the potential for arcing at themale connector 404 and/or the plug 108 is negligible regardless ofwhether the plug 108 is manually removed or auto-ejected by the start ofthe vehicle 112.

FIG. 6 illustrates an electrical schematic diagram of theauto-disconnect apparatus 100. As shown in FIG. 6, the plug 108 includesneutral, line, and ground connections that are configured to couple withcorresponding contacts in the male connector 404. The microswitch 202includes three contacts: normally open (NO), normally closed (NC), andcommon (C). The NC contact is not used in normal operation. A faultindicator 602 is connected to the NC contact. In some embodiments, ifthe plug 108 is inserted and a fault occurs in the power circuit of theauto-disconnect apparatus 100, the fault indicator 602 will illuminate.A power indicator 604 is connected to the NO contact. When the plug 108is inserted and the auto-disconnect apparatus 100 is operatingcorrectly, the power indicator 604 will illuminate. In some embodiments,the fault indicator 602 and the power indicator 604 are LED lamps.However, any other suitable indicator could be used.

Although FIGS. 1 through 6 illustrates one example of an auto-disconnectapparatus 100 for use in an electrical power connection, various changesmay be made to the figures. For example, certain ones of the variouscomponents of the auto-disconnect apparatus 100 may be combined,rearranged, duplicated, separated into sub-components, or replaced withother components.

In some embodiments, various functions described above are implementedor supported by a computer program that is formed from computer readableprogram code and that is embodied in a computer readable medium. Thephrase “computer readable program code” includes any type of computercode, including source code, object code, and executable code. Thephrase “computer readable medium” includes any type of medium capable ofbeing accessed by a computer, such as read only memory (ROM), randomaccess memory (RAM), a hard disk drive, a compact disc (CD), a digitalvideo disc (DVD), or any other type of memory. A “non-transitory”computer readable medium excludes wired, wireless, optical, or othercommunication links that transport transitory electrical or othersignals. A non-transitory computer readable medium includes media wheredata can be permanently stored and media where data can be stored andlater overwritten, such as a rewritable optical disc or an erasablememory device.

It may be advantageous to set forth definitions of certain words andphrases used throughout this patent document. The terms “application”and “program” refer to one or more computer programs, softwarecomponents, sets of instructions, procedures, functions, objects,classes, instances, related data, or a portion thereof adapted forimplementation in a suitable computer code (including source code,object code, or executable code). The terms “transmit” and “receive,” aswell as derivatives thereof, encompass both direct and indirectcommunication. The terms “include” and “comprise,” as well asderivatives thereof, mean inclusion without limitation. The term “or” isinclusive, meaning and/or. The phrase “associated with,” as well asderivatives thereof, may mean to include, be included within,interconnect with, contain, be contained within, connect to or with,couple to or with, be communicable with, cooperate with, interleave,juxtapose, be proximate to, be bound to or with, have, have a propertyof, have a relationship to or with, or the like. The phrase “at leastone of,” when used with a list of items, means that differentcombinations of one or more of the listed items may be used, and onlyone item in the list may be needed. For example, “at least one of: A, B,and C” includes any of the following combinations: A, B, C, A and B, Aand C, B and C, and A and B and C.

While this disclosure has described certain embodiments and generallyassociated methods, alterations and permutations of these embodimentsand methods will be apparent to those skilled in the art. Accordingly,the above description of example embodiments does not define orconstrain this disclosure. Other changes, substitutions, and alterationsare also possible without departing from the spirit and scope of thisdisclosure, as defined by the following claims.

What is claimed is:
 1. A power line disconnect apparatus comprising: ahousing; a connector plate coupled to the housing; an ejector pinconfigured to project through a first aperture in the connector plateand eject a plug of a power cable from an electrical connectorprojecting from a surface of the connector plate; a microswitchconfigured to activate and deactivate a power circuit associated withthe power cable; and a sensor pin configured to project through a secondaperture in the connector plate, the sensor pin having a sensor pinextension, the sensor pin extension configured to control themicroswitch.